1. Technical Field
The present invention relates to a recording apparatus, and particularly to a recording apparatus with an apparatus main body to which an extension unit can be attached.
2. Related Art
In the related art, recording apparatuses, each of which is provided with a sheet cassette containing stacked sheets as an example of a recording medium and a recording unit causing a liquid ejecting head, for example, to eject liquid onto the sheet sent from the sheet cassette and transported along a transport path to record images including characters and figures has been put into practical use.
There are some such recording apparatuses to which an extension unit (optional unit), such as an extension case configured as a separate unit from an apparatus main body, can be attached to and detached from the apparatus main body. For example, JP-A-2004-26438 discloses as the extension unit a unit which is detachably attached to a lower portion positioned on the side of the weight direction of the apparatus main body, and sends the sheet contained therein to the transport path in the apparatus main body.
In addition, the recording apparatus includes main body legs which are provided on the lower surface of the lower portion of the apparatus main body so as to be in contact with a placement surface when placed alone on the placement surface without the extension unit attached thereto. The main body legs are typically formed with an elastic material (rubber or elastomer, for example) in order to alleviate impact due to the contact with the placement surface when the apparatus main body is placed.
Incidentally, according to the recording apparatus, a temperature in the apparatus rises accompanying with heat generation in the recording unit during recording processing on the recording medium, and images cannot be correctly recorded in some cases due to a phenomenon in which an amount of liquid to be ejected from the liquid ejecting head varies due to the temperature rise. Accordingly, it is necessary to cool (air-cool) the recording apparatus by causing air (external air) to flow into the apparatus from the lower portion of the apparatus (apparatus main body) and discharging air warmed in the apparatus to the outside of the apparatus.
Thus, according to the recording apparatus, the apparatus main body is formed such that the main body legs form a gap between the lower surface of the lower portion and the placement surface in a state where the apparatus main body is placed on the placement surface. Air (external air) flows into the lower surface of the lower portion via the gap, and the external air flows from the lower portion into the apparatus through the gap formed in a case body of the apparatus main body, for example, during rising of the air warmed in the apparatus.
On the other hand, the main body legs are in contact with an upper surface of an upper portion, which is positioned on the side of a direction opposite to the weight direction, of the extension unit instead of the placement surface when the extension unit is attached to the lower portion of the apparatus main body. On this occasion, the main body legs form a gap between the upper surface of the upper portion of the extension unit and the lower surface of the lower portion of the apparatus main body.
However, although the main body legs, made of an elastic material, initially form a predetermined gap, the gap changes over time due to compression, and the deformation amount (crush amount) gradually increases, if the main body legs are in contact with the upper surface of the upper portion of the extension unit for a long time. As a result, the gap between the upper surface of the upper portion of the extension unit and the lower surface of the lower portion of the apparatus main body becomes narrower than that in the initial state, and there is a problem in that a flow amount of the air flowing into the apparatus main body from the lower portion becomes smaller. In addition, there is also a problem in that a length of the transport path for the sheet sent from the extension unit becomes shorter as the gap between the apparatus main body and the extension unit becomes narrower and variations in the transport conditions results in unstable transport.